Automotive and other styling models are used to verify styling concepts. Styling models are made from a wide variety of material including clay, wood and composite materials. Styling models are formed by skilled model makers. A problem with prior art methods of making styling models is the difficulty encountered in making an accurate and verifiable model which allows the modeling of interior and exterior surfaces in a modular manner.
Recently, computer aided design (CAD) has been applied to the styling process to allow visualization of styling models by means of computer graphics. With a CAD system a visual representation of a product or vehicle can be created, modified, rotated and manipulated. The problem with CAD images is that they are not as realistic as an actual model and it is not possible to sit in or walk around a CAD representation.
Design models can be traced to provide an input for a CAD system. An example, of this approach is disclosed in Zuccato U.S. Pat. No. 4,867,922. According to the Zuccato method of making a styling model, a mold is made and fiberglass material is applied to the internal surfaces of the mold. An epoxy-based material is then applied to the fiberglass, hardened and machined to define exterior visible surfaces. The mold is initially milled using the stored data obtained by tracing clay models of interior and exterior surfaces. The Zuccato process is a "one-off" process which cannot benefit from repeatability for sample parts. There is no provision for scanning changes and re-milling. The machined mold is destroyed in order to remove the fabricated part. There is no provision for the use of a soft medium such as clay as part of the finished model. According to this method, the definition of an interior surface is either symmetrically created, based upon the exterior surface or supplied by scanning or CAD sequence. No mechanism is disclosed for locating a component accurately, such as the door disclosed in Zuccato, in an overall styling model in a modular approach.
Another method for making styling models for exterior vehicle design is disclosed in U.S. Pat. Nos. 4,474,722 and 4,555,836 both issued to Martin. According to the method described in the Martin patents, hard surface non-modular styling models are made from styrofoam blocks which are shaped from templates and have their surface replaced with an epoxy resin in a two-step process. The method proposed by Martin is directed to exterior surface modeling and does not provide a verifiable interior and exterior method of modeling. The Martin process is likewise a "one-off" process lacking repetitive advantages and re-scanning capability to modify according to design changes.
In another approach to making models proposed by Nico, Jr. et al in U.S. Pat. No. 4,863,663, cardboard templates are made from cross-sectional drawings of a part taken at spaced intervals corresponding to drawing section lines to form a skeletal frame. Sheet material is bonded to the skeletal frame and then covered with a glass fiber layer and resin. Again, a verifiable method of modeling separable interior and exterior surfaces is not disclosed in the Nico method.
One of the problems encountered in making and using design models is the need to provide a model which may be modified in coordination with adjoining parts. Models must be able to be modified to reflect the changes in secondary surfaces, inner skin or outer skin surfaces, addition or deletion of features or components. Secondary surfaces correspond to boundaries of vehicle parts such as the sides of doors.
Frequently, designers are called upon to develop styling models wherein style changes must be made for different models. For example, in the automotive styling process, related models made on common body platforms are modified by providing different feature elements. For example, a door provided on one style of vehicle can be modified by changing the arm rest and handle assembly or storage compartment features to create a different style of the vehicle. According to prior art techniques, the entire inner door panel and armature would need to be modeled again to allow for actual evaluation of the alternate style.
With prior art styling methods large monolithic fixtures are required to hold parts in their proper orientation. In particular, roof and window frame elements are generally supported by large armatures which interfere with the visualization of the upper passenger compartment. The styling of automotive windows in conjunction with styling models is not easily accomplished when such armatures are used because it is not normally possible to see through window areas when the armatures are in place.
These and other long-standing problems addressed by this invention are solved by a unique, unified approach which is summarized below.